This invention relates in general to a heated windshield system, and more specifically, to a power connection for providing power to a heated windshield system in a wet area in a vehicle.
Windshield defrost systems typically generate heat, in the form of forced air or conducted heat from window-mounted heating elements to defrost ice build up on a windshield. Heating elements integrated within the windshield offer a uniform and even defrost pattern across the windshield as opposed to forced air. The heating elements include a plurality of fine wires that are embedded within a vinyl intermediate layer of the windshield. The vinyl intermediate layer is sandwiched between two glass panes. Electrical current is conducted through the fine wire elements for defrosting the windshield. The electrical current carried through the fine wires causes an increase in the temperature of the wire element which is transferred to the glass. The heat melts ice build up on the windshield and evaporates moisture formed thereon.
A typical heated windshield utilizing fine heating wire elements requires the use of a large amount of power, such as 300 Watts to 1200 Watts. This power is obtained by applying a specific voltage to a predetermined resistance to achieve the desired heat in the glazing system. Power is supplied to the windshield glazing system from an external power source, such as a vehicle battery, alternator, or other device. In order to obtain proper heating of the heating wire elements, power to the heating wire elements must be transmitted from the power source to the windshield glazing system without any significant power loss, especially through the connector. The connector must be able to withstand exposure to environmental elements such as moisture (i.e., water) or chemical solvents such as windshield washer solvent.
A typical connector for a windshield defrost system is electrically connected to the windshield glazing system in the upright pillars (i.e., A-pillars) of the supporting vehicle body frame of the windshield. The connector is typically coupled to a power source harness in the A-pillar. The internal structure of the A-pillar is considered a dry-environment which is typically protected from environmental conditions external to the vehicle. While packaging the connector in the A-pillar maintains a dry environment for the connector, it may be disadvantageous to access the connector. For windshield systems where the windshield and the windshield glazing system connectors are provided as a preassembled package for assembly to the vehicle, access to the connector as well as packaging the connector within the A-pillar as it is assembled may be difficult.
For a windshield heating system where the electrical connection is made at the bottom of the windshield, ample space is usually available near the engine compartment (i.e., cowl area) located below the windshield for packaging the electrical connector. However, this location is considered a wet environment as water run-off from the windshield is directed and routed through this region. A connector packaged in this location must be capable of withstanding the water and its freezing corrosive effects as well as thermal cycling caused from the outside ambient weather conditions and the temperatures generated by the heat of an operating engine.